Guanidinium salts of n-alkylmaleamic acids



American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application April 21, 1953, 3

Serial No. 350,256 1 Claims. (Cl; 260-501) This invention relates to guanidiniu'm'salts of higher N-alkylmaleamic acids wherein the aliphatic 'or alkyl radical contains from 8 to 18 or more carbon atoms. The invention includes the new salts themselves, their methods of preparation and also textile treating and finishing compositions containing them as will hereinafter be more fully described. I

The higher N-alkylmaleamic acids, wherein the alkyl radical contains 8 or more carbon atoms, can be prepared by reacting maleic anhydride with higher primary aliphatic amines. We have found that the guanidinium salts of these acids can be formed by the methods hereinafter described and that these salts possess a number of valuable properties. Thus, for example, we found that they function as antistatic agents when applied to'synthetic textile filaments such as threads or yarns of viscose, rayon, Orlon, nylon and the like. Many of the guanidinium salts, and particularly the guanidine and biguanide salts of N-octadecylmaleamic acid, possess excellent softening properties for cotton and rayon cloth. All of our new salts possess foaming and detergent propertiesfin Water solution and a number of them, including particularly the biguanide, the phenylg'uanidine, and the 'phenylbinited aticnt guanide salts, possess definite antioxidant and metal deactivating properties. These salts are therefore valuable addition agents to soap, since they serve as combined detergents and soap antioxidants.

Our new salts are most easily prepared by mixing a guanidinium salt of a volatile weak acid, such as the carbonate or bicarbonate, with the desired higher N-alkylmaleamic acid. Preferably an aqueous solution of the guanidinium salt is employed, and the mixture is heated with agitation at 7090 C. for about /2 hour, or until the desired salt formation is complete; Other methods of preparation may, however, be employed; thus, for example, guanidine sulfate, biguanide sulfate or'other guanidinium sulfates may be reacted with barium hydroxide in aqueous solution'to liberate the free base which may I,

then be reacted with the N-alkylmaleamic acid.

The term guanidinium salts of N-alkylmalearnic acids, as used in the present specification and claims, .is

intended to designate the salts of the class of guanidines generally, including the unsubstituted and substituted guanidines, biguanides and guanylureas, the term guanidine salts being used to describe the'salts of guanidine itself. This terminology is based on the recognition that the biguanides and guanylureas are guanyl-sub'stituted and carbamyl-substituted 'guanidines, respectivelfi therefore the entire group of salt-forming compounds-is properly designated as the guanidines and substituted guanidines. The preferred guanidinium salts of our invention are defined accurately by the formula R.NH.C: (NH) .NH.X.HO.OC.CH=CH.CO.NVHR

in which R is an alkyl radical of from 8 to 18 or more carbon atoms, R is hydrogen or an alkyl or phenyl radi- 2,739,168 Patented Mar. 20, 1956 Any desired unsubstituted or substituted guanidine, guanylurea or biguanide may be used to prepare addition salts of higher N-alkylmaleamic acids in accordance with our invention. A' large number of guanidinium salts which may be so used, including their methods of preparation, are described in U. S.-Patent No, 2,265,944, and any of the bases described in this patent may be used to prepare higher N-alkylmaleamic acid salts in accordance with our invention. The preferred salts are those pre pared with guanidine, mono-alkyl guanidines such as methyl or ethyl guanidine, butyl guanidine, octadecyl guanidine', and the like, prepared by reacting salts of the corresponding primary amines with 'cyanamide, phenylguanidine, and the corresponding biguanides and guanylureas. Typical compounds of this class are described in detail in the following specific examples. 7

Any 'N-alkylmaleamic acid wherein the alkyl radical contains 8 or'more carbon atoms may be used. Where the guanidinium salts are intended for use as soap antioxidants, compounds in which thealkyl group contains from 8 to about 12 carbon atoms are preferred, whereas those containing alkyl radicals of 12 to 18 or more carbon atoms are the most effective softening agents and antistatic agents for textiles. All of these compounds are most easily prepared by condensingmaleic anhydride with the corresponding primary aliphatic amines; however, fumaric acid or maleic acid may be used instead of maleic anhydride if desired.

The new compounds of our invention are light-colored, waxy solids, all of which are water-dispersible but most .of which are only water-soluble to the extent of a few percent. Dilute aqueoussolutions containing them foam on shaking and exhibit definite detergency. The compounds are easily applied to textiles,'paper and other materials by soaking them in such solutions, followed by drying. Most of our new salts are also soluble in ethanol and other volatile polar organic solvents.

Our invention will befurther illustrated by the follow- 7 ing specific examples, which describe the preparation of particular guanidinium salts includedtherein.

EXAMPLE 1 I I Preparation of N-oc tadecylm aleamic acid A commercial octadecylar nine was driedby heating un der vacuum at C. for two hours and a portion weighing 2216 grams (8 mols) was Weighed out.

A beaker equipped with a stirrer was charged with 1 13 grams (0.3 mol) of the N-octadecylmaleamic acid of Exby titration with sodium triple l which was then melted. A solution of 27.5 grams 0.15 mol) of guanidine ,carbonate dissolved in 400 cc. if water was added and the mixture was stirred slowly .t 45 55 C. for about 2-3 hours. At the end of this ime the salt formation was complete and a smooth slurry :ontaining 26.5% solids was obtained. The water was :vaporated by tray drying in a current of warm air, leavmg the guanidine N-octadecylmaleamate as a light tan ,olid which was soluble in water to a turbid 1% solution.

The compound was tested as a softener for 5.2 oz. mer :erized cotton twill and medium weight rayon suiting by )assing the fabrics through its dilute aqueous solution lsing a pad mangle, adjusted to retain a weight of solution :qual to the weight of the fabric, followed by drying on a :rarne for minutes at 250 F. The treated fabrics were hen evaluated by comparing their softness with the unireated fabrics and with other samples treated with cornnercially acceptable softeners. Both fabrics were rated good when impregnated with 1% and with 0.25% of he softener; in both cases they were rated as being much better than the commercial standard.

EXAMPLE 3 Biguanide N-octadecylmaleamizt'e Free biguauide was prepared by treating 45 grams (0.15 mol) of biguanide sulfate in 400 cc. of water with 47.3 grams of bariiun hydroxide in 600 cc. of water and filtering off the barium sulfate.

The resulting biguanide solution was added to 117 grams (0.3 mol) of molten N-octadecylmaleamic acid during ten minutes and the mixture was stirred on a steam bath for 90 minutes. Upon cooling it formed a firm white paste containing solids. At 1% concentration a water solution was turbid at 50 C. and precipitated at room temperature.

When applied to cotton and rayon cloth and tested as described in Example 2, the softness rating was good both at 1% and at 0.25% concentration and was better than that of the commercial softener used as a standard of comparison.

EXAMPLE 4 Guanylurea N-octaaecylmaleamate Phenylguanidine N-octadecylmaleamate To 78 grams (0.2 mol) of the product of Example 1 there was added a slurry of 45 grams (0.2 mol) of phenylguanidine (as a carbonate-bicarbonate mixture with a purity of 77%) in 800 cc. of water. The reaction mixture was refluxed for 2 hours. Upon cooling to room temperature the 10% slurry separated into a liquid and a solid phase. It was dispersible at 1% in water.

EXAMPLE 6 Guanidine N-dodecylmaleamate Using the apparatus and procedure of Example 1, 92.5 grams (0.25 mol) of dodecylamine was added in onehalf hour to 49.5 grams (0.505 mol) of molten maleic anhydride. Stirring was continued at 80-90 C. for an additional one-half hour after which the resulting N-doof 46 grams (0.25 mol) of guanidine carbonate in 475 cc.

of water. The mixture was stirred on a steam bath for two hours at 80-85 C. and then cooled and allowed to stand at room temperature, whereupon it formed a white 25% slurry. The guanidine N-dodecylmaleamate was recovered from this slurry as a white solid that formed an opalescent 1% solution in water.

EXAMPLE 7 Guanidine Noctylmaleamate To 99 grams (1.01 mols) of molten maleic anhydn'de there was added 129 grams (1 mol) of n-octylamiue over a period of 45 minutes at 63 75 C. and the mixture was stirred for 15 minutes at 95 C. The resulting N- octylmaleamic acid was neutralized by adding 93 grams (0.5 mol) of guanidine carbonate dissolved in 300 cc. of water and stirring for 30 minutes at -95 C., followed by cooling. At room temperature an amber colored clear solution of 28% solids content was formed, from which the solid guanidine N-octylmaleamate was recovered by evaporation to dryness.

EXAMPLE 8 Phenylbiguanide N -0ctadecylmaicamate A portion of the N-octadecylmaleamic acid of Example 1 weighing 78 grams (0.2 mol) was neutralized with a solution of 36 grams (0.2 mol) of phenylbiguanide in 500 cc. of water. The mixture was stirred on a steam bath at 75-85 C. for 30 minutes and then cooled. At room temperature it was a thin tan paste having a solids content of 18%. A 1% aqueous solution was viscous and turbid.

EXAMPLE 9 N -b utylgl zanidine N -0ctaa'ecyl maleanmte A solution of 43.5 grams (0.2 mol) of N-butylguanidine sulfate in 500 cc. of water was treated with 31.6 grams of barium hydroxide in 400 cc. of water.

After filtering ofi the precipitated barium sulfate the free N-butylguanidine solution was added to 78 grams (0.2 mol) of molten N-octadecylmaleamic acid during fifteen minutes. The mixture was stirred on a steam bath for 2 hours. The smooth mixture was poured into a tray and the water evaporated with a current of warm air. The resulting N-butylguanidine N-octadecylmaleamate was a light brown solid which dissolved in water to form turbid 1% solutions.

What we claim is:

1. Guanidinium salts of N-alkylmaleamic acids wherein the alkyl radical contains from 8 to 18 carbon atoms.

2. N-alkylrnalearnic acid salts of the formula References Cited in the file of this patent UNITED STATES PATENTS Jaeger et a1 Aug. 21, 1945 

1. GUANIDINIUM SALTS OF N-ALKYLMALEAMIC ACIDS WHEREIN THE ALKYL RADICAL CONTAINS FROM 8 TO 18 CARBON ATOMS. 